Discovery filed suit today in the US District Court for the District of Delaware, alleging infringement of a patent filed by the company in September of 1999. Describing an "Electronic Book Security and Copyright Protection System," the patent was awarded in 2007, with Discovery founder John S. Hendricks listed among the inventors.

"The Kindle and Kindle 2 are important and popular content delivery systems," reads a canned statement from Discovery general counsel Joseph A. LaSala Jr. "We believe they infringe our intellectual property rights, and that we are entitled to fair compensation.

"Legal action is not something Discovery takes lightly. Our tradition as an inventive company has produced considerable intellectual property assets for our shareholders, and today’s infringement litigation is part of our effort to protect and defend those assets."

Discovery and the law firm representing the company did not immediately respond to a request for comment. Amazon declined to comment.

Discovery - known for the Discovery Channel, TLC, Animal Planet, and other cable networks - is objecting not only to the Kindle and its recently-announced sequel, the Kindle 2, but also to Amazon's online delivery system. Amazon delivers ebooks over something it calls WhisperNet, which runs over Sprint's EVDO wireless network.

"Amazon's infringing activities...include the operation of the Amazon.com website and the provision of services related to the Kindle and Kindle 2 through and by the website, including but not limited to the sale of electronic books," the suit reads.

The patent describes a system that "provides for secure distribution of electronic text and graphics to subscribers and secure storage." This covers distribution to bookstores, public libraries, and schools as well as consumers equipped with a "home subsystem." As described, delivery may involve everything from television, telephone, and radio networks to the internet.

"The home subsystem connects to a secure video distribution system or variety of alternative secure distribution systems, generates menus and stores text, and transacts through communicating mechanisms," the patent abstract reads. "A portable book-shaped viewer is used for secure viewing of the text. A billing system performs the transaction, management, authorization, collection and payments utilizing the telephone system or a variety of alternative communication systems using secure techniques."

In February, the US Author's Guild complained that the Kindle 2's new text-to-speech feature violated copyright law because it "reads" books aloud without paying author's extra royalties. "They don't have the right to read a book out loud," Paul Aiken, executive director of the Authors Guild, told the Wall Street Journal. "That's an audio right, which is derivative under copyright law."

But the publishing industry has yet to actually file suit. Amazon has now said that it will allow publishers to opt-out of the new text-to-speech feature. ®